Probe manufacturing method, probe, and scanning probe microsope

ABSTRACT

A method of producing a probe by attaching a carbon nanotube etc. to a mounting base end and bonding it there using a carbon film etc., which method of producing a probe eliminates the effects of a carbon contamination film to increase the bonding strength, increases the conductivity of the probe, and strengthens the bonding performance by coating the entire circumference rather than coating one side, the probe, and a scanning probe microscope are provided.  
     The method of producing a probe is a method of producing a probe comprised of a carbon nanotube  12 , a mounting base ends  13  holding this carbon nanotube, and a coating film  17  bonding the carbon nanotube to a mounting base, comprising performing the mounting work of the carbon nanotube and mounting base end under observation by a microscope and stripping off the carbon contamination film  14  formed by an electron microscope at a stage before bonding by the coating film.

TECHNICAL FIELD

The present invention relates to a method of producing a probe suitablefor stably mounting a nanotube at a base member with a sufficientbonding strength in a scanning probe microscope provided with a probeutilizing a carbon nanotube as a probe tip, such a probe, and such ascanning probe microscope.

BACKGROUND ART

In recent years, scanning probe microscopes and electron microscopesusing carbon nanotubes and other nanotubes as tips of probes have beenproposed (Patent Document 1). Nanotubes are utilized in scanning probemicroscopes as probe tips provided at the front ends of cantilevers andare utilized in electron microscopes as electron source probes. PatentDocument 1 generally discloses a surface signal scan probe forelectronic apparatuses and a method of producing the same. Electronicapparatuses include scanning probe microscopes. The probe disclosed inPatent Document 1 is produced utilizing carbon nanotubes and othervarious types of nanotubes. This is so as to try to realize a highresolution, high rigidity, and high bending modulus probe. In probe tipsof scanning probe microscopes, research and studies have been conductedto increase the resolution from the viewpoint of how to make themsharper. In this sense, nanotubes may become important technology forthe future.

Patent Document 1 (Japanese Patent Publication (A) No. 2000-227435)discloses an example of a method of producing a probe utilizing a carbonnanotube. A carbon nanotube is easy to produce, is inexpensive, and issuitable for mass production. The Patent Document 1 explains as anoptimal method of production the method of production usingelectrophoresis to arrange a carbon nanotube at a metal plate of aholder etc. The carbon nanotube arranged at the holder is mounted at amounting base end in the state attached to the holder. The mounting baseend is for example the probe tip of an atomic force microscope. Thismounting work (assembly work) is performed while positioning underobservation by a scanning electron microscope (SEM). After the mountingwork, the region including the mounting base end is formed with acoating film so as to bond the carbon nanotube to the mounting base end.As the method for forming the coating film, the method of using electronbeam irradiation based on an SEM to form a carbon film, the method ofbreaking down reactive coating gas by an electron beam to form a coatingfilm, and also the examples of CVD or PVD have been proposed. The carbonfilm formed by electron beam irradiation based on an SEM is usuallycalled a “carbon contamination film”. Further, technology for forming acoating film at an intermediate part between the carbon nanotube andmounting base end to form a coating film and increase the carbonnanotube in thickness and strength has already been proposed.

According to the method of producing a probe utilizing a nanotubedescribed in the above Patent Document 1, the problem arises that theproduced probe is insufficient in strength. That is, when bonding thecarbon nanotube to the mounting base end, the bonding coating film isformed via the carbon contamination film arising due to SEM observation,so the bonding strength becomes insufficient. Further, whenstrengthening a probe made using a carbon nanotube, since only one sideis coated, sufficient strengthening is not possible. Further, since thebonding is via a carbon contamination film, the problem also arises thatthe conductivity is difficult to secure.

[Patent Document 1] Japanese Patent Publication (A) No. 2000-227435

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

The subject of the present invention is to increase the bonding strengthby a bonding means, increase the conductivity performance of a probe,and improve the bonding performance of the bonding means when producinga probe by mounting a carbon nanotube etc. to a mounting base end andbonding them by a bonding coating film or other bonding means.

An object of the present invention, in view of the above subject, is toprovide a method of producing a probe by mounting a carbon nanotube etc.to a mounting base end and using a carbon film for bonding which methodof producing a probe can eliminate the effects of the carboncontamination film etc., improve the bonding strength, improve theconductivity of the probe, and further strengthen the bondingperformance by coating the entire circumference rather than one-sidedcoating.

Another object of the present invention is to provide a probe having ahigh bonding strength and high conductivity and a scanning probemicroscope provided with such a probe.

MEANS FOR SOLVING THE PROBLEM

The method of producing a probe, probe, and scanning probe microscopeaccording to the present invention is configured as follows to achievethe above objects.

The method of producing a probe according to the present invention is amethod of producing a probe comprised of a carbon nanotube or othernanotube, a base (mounting base end) holding this nanotube, and abonding part (coating film etc.) bonding the nanotube to the base, whichmethod comprises performing the work of attaching the nanotube and baseunder observation by an observation device and, at a stage beforebonding by the bonding part, stripping a contamination film formed bythe observation device.

In the above method of producing a probe, the contamination film isremoved at a stage before bonding using the bonding part of thecontamination film. Due to this, the surface of the nanotube is exposed.Therefore, when bonding the nanotube and base after this, the coatingfilm etc. is directly bonded to the nanotube, the problem of theinsufficient strength due to the contamination film is eliminated, andthe bonding strength can be improved. Further, by suitably eliminatingthe contamination film, the probe can also be enhanced in conductivity.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably theobservation device is an electron microscope and the contamination filmis a carbon film.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the carbonfilm is removed by focused ion beam processing.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the carbonfilm is removed by heating.

The method of producing a probe according to the present invention is amethod of producing a probe comprised of a nanotube, a base holding thisnanotube, and a bonding part bonding the nanotube to the base,characterized in that the bonding by the bonding part is performed afterreattaching the nanotube from the holder to which it had been attachedto the base.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the bondingby the bonding part is performed while rotating the nanotube and baseabout their axes.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably a bondingregion formed by the bonding part is formed near the end of the base.

The method of producing a probe according to the present invention isfor producing a probe comprised of a nanotube, a base holding thisnanotube, and a bonding part bonding the nanotube to the base,characterized in that the bonding by the bonding part is performed whilerotating the nanotube and base about their axes. Since the bonding partis formed at the entire circumference of the part where the nanotube andthe base are bonded, the strength of the bond becomes higher than thecase of just a single side.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the bondingby the bonding part is performed after reattaching the nanotube from theholder to which it is attached to the base.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the bondingpart is a carbon film formed by electron beam irradiation.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the bondingpart is a film of a substance formed by introducing a reactive gas andelectron beam irradiation.

The method of producing a probe according to the present inventionprovides the above method of production wherein preferably the bondingpart is a film of a substance formed by focused ion beam irradiation.

The scanning probe microscope according to the present invention isprovided with a probe tip part provided so that a probe tip faces asample and a measurement part for measuring a physical quantityoccurring between the probe tip and sample when the probe tip scans thesurface of the sample, wherein this measurement part holds the physicalquantity constant while the probe tip scans the surface of the sample soas to measure the surface of the sample, the probe tip is comprised of ananotube, a base holding this nanotube, and a bonding means for bondingthe nanotube to the base, and a contamination film formed by anobserving means is stripped off at a stage before bonding by the bondingmeans.

The scanning probe microscope according to the present invention isprovided with a probe tip part provided so that a probe tip faces asample and a measurement part for measuring a physical quantityoccurring between the probe tip and sample when the probe tip scans thesurface of the sample, wherein this measurement part holds the physicalquantity constant while the probe tip scans the surface of the sample soas to measure the surface of the sample, the probe tip is comprised of ananotube, a base holding this nanotube, and a bonding means for bondingthe nanotube to the base, and the bonding means is a coating filmprovided over the entire circumferences of the nanotube and base.

In the scanning probe microscope, the probe tip part is a cantileverhaving the probe tip at its front end.

The probe according to the present invention is used for a scanningprobe microscope or electron microscope, is provided with a probe tipcomprised of a nanotube, a base holding this nanotube, and a bondingmeans bonding the nanotube to the base, and is stripped of acontamination film formed by an observing means at a stage beforebonding by the bonding means.

Alternatively, the probe according to the present invention is used fora scanning probe microscope or electron microscope and is provided witha probe tip comprised of a nanotube, a base holding this nanotube, and abonding means bonding the nanotube to the base, the bonding means beinga coating film provided over the entire circumferences of the nanotubeand base.

EFFECT OF THE INVENTION

According to the method of producing a probe of the present invention,there is provided a method of producing a probe by attaching a nanotubeto a mounting base end under observation by an SEM etc. and bonding thethem by a coating film etc. wherein a carbon contamination film formeddue to the SEM etc. is stripped off at a stage before the bonding workto enable bonding without the effects of the carbon contamination filmetc., so the nanotube and mounting base end may be directly bonded, thestrength may be improved, and the conductivity may be improved.According to the present invention, when detaching the holder from thenanotube after the mounting work, the contamination film is broken andthe surface of the nanotube is exposed.

According to the probe of the present invention, it is possible toincrease the bonding strength and increase the conductivity. Further, byusing this probe as an AFM probe, it is possible to utilize this as AFMlithography based on its high conductivity.

According to the scanning probe microscope of the present invention, byproviding a probe having a high bonding strength and conductivity, it ispossible to raise the durability of the device and possible to releasethe charge due to the high conductivity so eliminate the effects ofstatic electricity and thereby improve the measurement accuracy.

BEST MODE FOR WORKING THE INVENTION

Below, preferred embodiments of the present invention will be explainedbased on the attached drawings.

Referring to FIG. 1, the method of producing a probe according to afirst embodiment of the present invention will be explained. In FIG. 1,11 indicates a holder (metal sheet), 12 a carbon nanotube, and 13 amounting base end. The carbon nanotube 12 is produced by for example theelectrophoresis method and is obtained in the state attached to theholder 11. The carbon nanotube 12 is a cylindrical member with across-sectional diameter of 1 nm to several tens of nm. The mountingbase end 13 is for example a probe tip formed at a cantilever used foran atomic force microscope. This probe tip, that is, the mounting baseend 13, is usually produced utilizing semiconductor film formingtechnology etc. The carbon nanotube 12 is attached and bonded to thefront end of the mounting base end 13, whereby a probe is assembled andproduced.

In FIG. 1, three partial views (A), (B), and (C) are used to show steps1 to 3 of the method of production. At step 1, the holder 11 is used toattach a carbon nanotube 12 to the front end of the mounting base end13. A carbon film is formed (carbon contamination film 14) and a bondingcoating film 15 is used to bond the carbon nanotube 12 and the mountingbase end 13. At step 1, as shown by the arrow 16, force is applied toseparate the holder 11 from the carbon nanotube 12. The results areshown in step 2.

At step 2 of (B) in FIG. 1, the holder 11 is separated from the carbonnanotube 12. At this time, the carbon contamination film 14 is alsopartially shredded and separated together with the holder 11. As aresult, at the right part of the carbon nanotube 12 shown in (B) of FIG.1, a part arises where there is no carbon contamination film andtherefore a part of the carbon nanotube 12 forming the surface isexposed.

At step 3 of (C) of FIG. 1, the carbon contamination film 14 is peeledoff and the exposed part of the surface of the carbon nanotube 12 isutilized to again form a bonding coating film 17. The new bondingcoating film 17 is formed to cover the exposed part of the carbonnanotube 12, the remaining carbon contamination film 14, and the firstbonding coating film 15. In this way, the carbon nanotube 12 is bondedto the mounting base end 13 by the new bonding coating film 17 after theattachment work and after detachment of the holder 11.

According to the first embodiment, the bonding coating film 17 is usedto bond the carbon nanotube 12 and the mounting base end 13. The bondingis performed in the state after removing the carbon contamination film14 to eliminate its effects. Further, the new bonding coating film 17 isused to bond the carbon nanotube 12 and the mounting base end 13 nearthe front end or at a projecting part of the mounting base end 13. Dueto the above, direct bonding becomes possible and an improvement of thebonding strength and improvement conductivity can be achieved.

Referring to FIG. 2, a method of producing a probe according to a secondembodiment of the present invention will be explained. In FIG. 2,elements the same as elements explained in FIG. 1 are assigned the samereference notations and explanations are omitted. Steps 1 to 3 of (A) to(C) are basically the same as the case of the first embodiment. In FIG.2, 11 indicates a holder, 12 a carbon nanotube, 13 a mounting base end,14 a carbon contamination film, 15 a first bonding coating film, and 21a new bonding coating film added after bonding.

In the method of producing a probe according to the second embodiment,due to the relationship of the carbon contamination film 14 and bondingcoating film 15, a wide region 22 with no coating film is secured.Therefore, when bonding again by the bonding coating film 21 at step 3,the area of the surface of the bonding coating film 21 is increased andthe bonding portion is formed including a part in addition to near theend of the mounting base end 13.

According to the method of producing a probe of the second embodiment,it is possible to increase the region of the exposed part of the carbonnanotube 12, possible to increase the region directly contacting thebonding coating film 21, and possible to improve the bonding strength.

Referring to FIG. 3, a method of producing a probe according to a thirdembodiment of the present invention will be explained. In FIG. 3,elements the same as elements explained in FIG. 1 or FIG. 2 are assignedthe same reference notations and explanations are omitted. (A) to (C) ofFIG. 3 show steps 1 to 3 of the method of producing a probe according tothe third embodiment. In FIG. 3, 11 indicates a holder, 12 a carbonnanotube, 13 a mounting base end, 14 a carbon contamination film, and 31a bonding coating film.

In the method of producing a probe according to the third embodiment, atstep 1, the holder 11 provided with the carbon nanotube 12 is attachedto the mounting base end 13. At this time, the holder 11 and carbonnanotube 12 and the mounting base end 13 are bonded by the carboncontamination film 14. In this state, at step 2, before the coatingwork, part of the carbon contamination film 14 is removed. The carboncontamination film 14 is removed using for example a method using afocused ion beam (FIB) or a method using heating. After this, as shownat step 3, the bonding coating film 31 is formed between the carbonnanotube 12 and the mounting base end 13. After this, at a suitabletiming, the holder 11 is removed.

According to the third embodiment, before the coating work for formingthe bonding coating film 31, it is possible to remove part of the carboncontamination film 14 and bring the bonding coating film 31 into directcontact with the carbon nanotube 12, reliably eliminate the effect ofthe carbon contamination film 14, and enlarge the direct contact area toincrease the strength of the bond.

Referring to FIG. 4, a method of producing a probe according to a fourthembodiment of the present invention will be explained. In FIG. 4,elements the same as elements explained in FIG. 1, FIG. 2, etc. areassigned the same reference notations and explanations are omitted. (A)to (C) of FIG. 4 show steps 1 to 3 of the method of producing a probeaccording to the fourth embodiment. This fourth embodiment is amodification of the second embodiment. In FIG. 4, 11 indicates a holder,12 a carbon nanotube, 13 a mounting base end, 14 a carbon contaminationfilm, and 15 a bonding coating film. The state shown by step 1 of (A) inFIG. 4 is the same as the state shown by step 1 of (A) in FIG. 2.

In the fourth embodiment, at the stage of transition from step 1 to step2, the holder 11 is separated from the carbon nanotube 12, then, asshown by the arrow 41, the carbon nanotube 12 is arranged so as to matchwith the axis of rotation and the mounting base end 13 is rotated whileperforming coating work for imparting a bonding coating film. For thisreason, as shown by (C) in FIG. 4, the entire circumference of thecarbon nanotube 12 can be given the bonding coating film 42. Moreparticularly, the bonding part between the carbon nanotube 12 and themounting base end 13 and the surrounding part including that bondingpart are given the bonding coating film 42 over the entire circumferencein the circumferential direction. The rotation drive mechanism used maybe one of any configuration.

In the above, the coating film 42 is a carbon film formed by electronbeam irradiation, a film of a desired substance formed by introducing areactive gas and by electron beam irradiation, or a film of a desiredsubstance deposited by FIB irradiation.

According to the fourth embodiment, since a new bonding coating film canbe provided over the entire circumference, the contact region betweenthe carbon nanotube and the bonding coating film can be increased, thebonding strength can be improved, and the conductivity can be improved.

In the above embodiments, as the bonding coating film, a carbon filmformed by electron beam irradiation, a film of a desired substanceformed by introducing a reactive gas and by electron beam irradiation, afilm of a desired substance deposited by focused ion beam irradiation,etc. is used.

Next, an example of a scanning probe microscope provided with a probeproduced by the above-mentioned method of production will be explainedwith reference to FIG. 5. This scanning probe microscope envisions as atypical example an atomic force microscope (AFM).

The bottom part of the scanning probe microscope is provided with asample stage 111. The sample stage 111 carries a sample 112 on it. Thesample stage 111 is a mechanism for changing the position of the sample112 by a three-dimensional coordinate system 113 comprised of aperpendicular X-axis, Y-axis, and Z-axis. The sample stage 111 iscomprised of an XY-stage 114, Z-stage 115, and sample holder 116. Thesample stage 111 is usually comprised of a rough (or coarse) movementmechanism causing displacement (change of position) at the sample side.The sample stage 111 has a sample holder 116 on the top surface of whicha relatively large area, sheet shaped sample 112 is placed and held. Thesample 112, for example, is a substrate or wafer on the surface of whichan integrated circuit pattern of a semiconductor device is fabricated.The sample 112 is fixed on the sample holder 116. The sample holder 116is provided with a sample-fixing chuck mechanism.

In FIG. 5, at a position above the sample 112, an optical microscope 118provided with a drive mechanism 117 is arranged. The optical microscope118 is supported by the drive mechanism 117. The drive mechanism 117 iscomprised of a focus use Z-direction movement mechanism 117 a for movingthe optical microscope 118 in the Z-axis direction and an XY-directionmovement mechanism 117 b for moving it in the X-and Y-axis directions.Due to the way they are attached, the Z-direction movement mechanism 117a moves the optical microscope 118 in the Z-axis direction, while theXY-direction movement mechanism 117 b moves the unit of the opticalmicroscope 118 and the Z-direction movement mechanism 117 a in the X-andY-axis directions. The XY-direction movement mechanism 117 b is fixed toa frame member, but in FIG. 5, illustration of the frame member isomitted. The optical microscope 118 is arranged so that its object lens118 a faces downward and is arranged at a position approaching thesurface of the sample 112 from directly above it. The optical microscope118 is provided at its top end with a camera 119. The camera 119captures an image of a specific area of the sample surface covered bythe object lens 118 a and outputs the image data.

Above the sample 112, a cantilever 121 provided with a probe tip 120 atits front end is arranged in a close state. The cantilever 121 is fixedto a mount 122. The mount 122, for example, is provided with an airsuction part (not shown). This air suction part is connected to an airsuction device (not shown). The cantilever 121 is affixed and mounted sothat this large area base is held by suction on the suction part of themount 122.

As the probe tip 120, the above-mentioned probe is used. The probe tip120 is formed with a mounting base end 13 and a carbon nanotube 12. Thefront end of the probe tip 120 is formed by the carbon nanotube 12attached to the front end of the probe.

The mount 122 is attached to a Z-fine movement mechanism 123 causingfine movement in the Z-direction. Further, the Z-fine movement mechanism123 is attached to the bottom surface of a cantilever displacementdetector 124.

The cantilever displacement detector 124 has a mechanism attaching alaser light source 126 and a photodetector 127 to a support frame 125 ina predetermined relationship. The cantilever displacement detector 124and the cantilever 121 are held in a constant positional relationship,whereby the laser light 128 emitted from the laser light source 126 isreflected at the back surface of the cantilever 121 and strikes thephotodetector 127. This cantilever displacement detector is comprised ofan optical lever type optical detection device. This optical lever typeoptical detection device can detect any torsion, flexing, or otherdeformation at the cantilever 121.

The cantilever displacement detector 124 is attached to an XY-finemovement mechanism 129. The XY-fine movement mechanism 129 allows thecantilever 121 and probe tip 120 etc. to move by fine distances in theX- and Y-axis directions. At this time, the cantilever displacementdetector 124 is moved simultaneously, so the cantilever 121 and thecantilever displacement detector 124 are unchanged in positionalrelation.

In the above, the Z-fine movement mechanism 123 and the XY-fine movementmechanism 129 are usually comprised by piezoelectric devices. The Z-finemovement mechanism 123 and the XY-fine movement mechanism 129 make theprobe tip 120 move by fine distances (for example several to 10 μm,maximum 100 μn) in the X-axis direction, Y-axis direction, and Z-axisdirection.

The above XY-fine movement mechanism 129 is attached to theabove-mentioned not shown frame member to which the unit of the opticalmicroscope 118 is attached.

Due to the mounting relationship, the field of observation of theoptical microscope 118 includes a specific area of the surface of thesample 112 and the front end (back surface) of the cantilever 121including the probe tip 120.

Next, the control system of the scanning probe microscope will beexplained. The control system is comprised of a comparator 131,controller 132, first control device 133, and second control device 134.The controller 132 is for example a controller for realizing ameasurement mechanism using an atomic force microscope (AFM). Further,the first control device 133 is a control device for controlling thedrive operations of the plurality of drive mechanisms etc., while thesecond control device 134 is a higher control device.

The comparator 131 compares a voltage signal Vd output from thephotodetector 127 and a preset reference voltage (Vref) and outputs adifference signal s1. The controller 132 generates a control signal s2so that this difference signal s1 becomes 0 and gives this controlsignal s2 to the Z-fine movement mechanism 123. Receiving the controlsignal s2, the Z-fine movement mechanism 123 adjusts the cantilever 121in height position to maintain a constant distance between the probe tip120 and the surface of the sample 112. A control loop from thephotodetector 127 to the Z-fine movement mechanism 123 is a feedbackservo control loop for detecting the state of deformation of thecantilever 121 by the optical lever type optical detection device whenthe probe tip 120 scans the sample surface and maintaining the distancebetween the probe tip 120 and the sample 112 to a predetermined constantdistance based on the reference voltage (Vref). Due to this controlloop, the probe tip 120 is kept a constant distance from the surface ofthe sample 112. When scanning the surface of the sample 112 in thisstate, it is possible to measure relief shapes on the sample surface.

Next, the first control device 133 is a control device for driving thedifferent parts of the scanning probe microscope and is provided withthe following functional parts.

The optical microscope 118 is changed in position by the drive mechanism117 comprised of the focus use Z-direction movement mechanism 117 a andthe XY-direction movement mechanism 117 b. The first control device 133is provided with a first drive controller 141 and a second drivecontroller 142 for controlling the operations of the Z-directionmovement mechanism 117 a and XY-direction movement mechanism 117 b.

The image of the sample surface or cantilever 121 obtained in theoptical microscope 118 is captured by the camera 119 and acquired asimage data. The image data obtained by the camera 119 of the opticalmicroscope 118 is input to the first control device 133 and processed byan internal image processor 143.

In the feedback servo control loop including the controller 132 etc.,the control signal s2 output from the controller 132 means the heightsignal of the probe tip 120 in a scanning probe microscope (atomic forcemicroscope). The height signal of the probe tip 120, that is, thecontrol signal s2, can give information relating to the height positionof the probe tip 120. The control signal s2 including the heightposition information of the probe tip 120, as explained above, is givenfor controlling the drive operation of the Z-fine movement mechanism 123and is acquired by the data processor 144 in the control device 133.

The scan by the probe tip 120 of the sample surface for the measurementarea of the surface of the sample 112 is performed by driving theXY-fine movement mechanism 129. The drive operation of the XY-finemovement mechanism 129 is controlled by an XY-scan controller 145providing an XY-scan signal s3 to the XY-fine movement mechanism 129.

The drive operations of the XY-stage 114 and the Z-stage 115 of thesample stage 111 are controlled by an X-drive controller 146 outputtingan X-direction drive signal, a Y-drive controller 147 outputting aY-direction drive signal, and a Z-drive controller 148 outputting aZ-direction drive signal.

Note that the first control device 133, in accordance with need, isprovided with a storage (not shown) storing and preserving the setcontrol data, input optical microscope image data, data relating to theheight position of the probe tip, etc.

The second control device 134 is provided at a position above the firstcontrol device 133. The second control device 134 stores and runs ausual measurement program, sets and stores the usual measurementconditions, stores and runs an automatic measurement program, sets andstores measurement conditions, stores measurement data, processes themeasurement results, displays information on the display device(monitor) 135, and performs other processing. For setting themeasurement conditions, it has functions for setting basic matters suchas the measurement range and measurement speed and the angle ofinclination, setting measurement conditions for when measuring thedifferent inclinations and postures and other conditions of automaticmeasurement, and files for setting these conditions. Further, it isconfigured with a communication function and can be given a functionenabling communication with an external device.

To give the second control device 134 these functions, it is comprisedby a processing unit constituted by a CPU 151 and a storage 152. Thestorage 152 stores and preserves the program and condition data etc.Further, the second control device 134 is provided with an image displaycontroller 153, a communicator, etc. In addition, the second controldevice 134 is connected through an interface 154 to an input device 136.The input device 136 enables setting and changes of the measurementprogram, measurement conditions, data, etc. stored in the storage 152.

The CPU 151 of the second control device 134 provides higher controlinstructions etc. through the bus 155 to the different functional partsof the first control device 133 and is provided with image data and datarelating to the height position of the probe tip from the imageprocessor 143, the data processor 144, etc.

Next, the basic operation of the scanning probe microscope (atomic forcemicroscope) will be explained.

The front end of the probe tip 120 of the cantilever 121 is made toapproach a predetermined area of the surface of the semiconductorsubstrate or other sample 112 placed on the sample stage 111. Usually, aprobe tip approach mechanism constituted by the Z-stage 115 brings theprobe tip 120 close to the surface of the sample 112 and applies atomicforce to make the cantilever 121 flex. The amount of flexing due to theflexing of the cantilever 121 is detected by the above-mentioned opticallever type optical detection device. In this state, the probe tip 120 ismade to move over the sample surface to scan the sample surface(XY-scan). The XY-scan by the probe tip 120 of the surface of the sample112 performed by moving the probe tip 120 side by the XY-fine movementmechanism 129 (fine movement) or by moving the sample 112 side by theXY-stage 114 (rough movement) so as to create relative movement in theXY-plane between the sample 112 and the probe tip 120.

The probe tip 120 side is moved by giving an XY-scan signal s3 forXY-fine movement to the XY-fine movement mechanism 129 provided with thecantilever 121. The scan signal s3 for XY-fine movement is given fromthe XY-scan controller 145 in the first control device 133. On the otherhand, the sample side is moved by giving drive signals from the X-drivecontroller 146 and Y-drive controller 147 to the XY-stage 114 of thesample stage 11.

The XY-fine movement mechanism 129 is comprised utilizing apiezoelectric device and enables high precision and high resolutionscanning movement. Further, the measurement range measured by theXY-scan by the XY-fine movement mechanism 129 is restricted by thestroke of the piezoelectric device, so even at the maximum becomes arange determined by a distance of about 100 μm or so. According to theXY-scan by the XY-fine movement mechanism 129, a narrow range ismeasured. On the other hand, the XY stage 114 is comprised utilizing anelectromagnetic motor as the drive part, so this stroke can be increasedup to several hundred mm. According to the XY-scan by the XY-stage, awide range is measured.

In the above way, a predetermined measurement area on the surface of thesample 112 is scanned by the probe tip 120 and the amount of flexing ofthe cantilever 121 (amount of deformation due to flexing etc.) iscontrolled to become constant based on a feedback servo control loop.The amount of flexing of the cantilever 121 is controlled so as toconstantly match with a reference target amount of flexing (set byreference voltage Vref). As a result, the distance between the probe tip120 and the surface of the sample 112 is held at a constant distance.Therefore, the probe tip 120, for example, moves along (scans) thesurface of the sample 112 while following its profile. The height signalof the probe tip is obtained to enable measurement of the profile of thesurface of the sample 112.

The configurations, shapes, sizes (thicknesses), and layouts explainedin the above embodiments are only shown schematically to an extentenabling the present invention to be understood and worked. Further, thenumerical values and compositions (materials) are only shown forillustration. Therefore, the present invention is not limited to theexplained embodiments and can be changed in various ways within thescope of the technical idea shown in the claims.

INDUSTRIAL APPLICABILITY

The present invention utilizes a carbon nanotube or other nanotube as aprobe of a scanning probe microscope etc. It eliminates the influence ofthe carbon contamination film by bonding the nanotube and thereby isutilized as a probe having a high bonding strength and conductivity.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] Step diagrams showing a method of production according to afirst embodiment of the present invention.

[FIG. 2] Step diagrams showing a method of production according to asecond embodiment of the present invention.

[FIG. 3] Step diagrams showing a method of production according to athird embodiment of the present invention.

[FIG. 4] Step diagrams showing a method of production according to afourth embodiment of the present invention.

[FIG. 5] A view of the configuration of a scanning probe microscopeaccording to the present invention.

DESCRIPTION OF NOTATIONS

-   11 holder-   12 carbon nanotube-   13 mounting base end-   14 carbon contamination film-   15 bonding coating film-   16 bonding coating film-   21 bonding coating film-   31 bonding coating film-   42 bonding coating film

1. A method of producing a probe comprised of a nanotube, a base holdingthis nanotube, and a bonding means for bonding said nanotube to saidbase, which method comprises performing the work of attaching saidnanotube and said base under observation by an observing means and, at astage before bonding by said bonding means, stripping a contaminationfilm formed by said observing means.
 2. A method of producing a probe asset forth in claim 1, characterized in that said observing means is anelectron microscope and said contamination film is a carbon film.
 3. Amethod of producing a probe as set forth in claim 1, characterized inthat said carbon film is removed by focused ion beam processing.
 4. Amethod of producing a probe as set forth in claim 1, characterized inthat said carbon film is removed by heating.
 5. A method of producing aprobe comprised of a nanotube, a base holding this nanotube, and abonding means for bonding said nanotube to said base, characterized inthat the bonding by said bonding means is performed after reattachingsaid nanotube from the holder to which it had been attached to saidbase.
 6. A method of producing a probe as set forth in claim 5,characterized in that said bonding by said bonding means is performedwhile rotating said nanotube and said base about their axes.
 7. A methodof producing a probe as set forth in claim 5, characterized in that abonding part formed by said bonding means is formed near the end of saidbase.
 8. A method of producing a probe comprised of a nanotube, a baseholding this nanotube, and a bonding means for bonding said nanotube tosaid base, characterized in that the bonding by said bonding part isperformed while rotating said nanotube and said base about their axes.9. A method of producing a probe as set forth in claim 8, characterizedin that said bonding by said bonding means is performed afterreattaching said nanotube from the holder to which it is attached tosaid base.
 10. A method of producing a probe as set forth in claim 1,characterized in that said bonding means is a carbon film formed byelectron beam irradiation.
 11. A method of producing a probe as setforth in claim 1, characterized in that said bonding means is a film ofa substance formed by introducing a reactive gas and electron beamirradiation.
 12. A method of producing a probe as set forth in claim 1,characterized in that said bonding means is a film of a substance formedby focused ion beam irradiation.
 13. A scanning probe microscopeprovided with a probe tip part provided so that a probe tip faces asample and a measurement part for measuring a physical quantityoccurring between said probe tip and said sample when said probe tipscans the surface of said sample, wherein this measurement part holdssaid physical quantity constant while said probe tip scans the surfaceof said sample so as to measure the surface of said sample, said probetip is comprised of a nanotube, a base holding this nanotube, and abonding means for bonding said nanotube to said base, and acontamination film formed by an observing means is stripped off at astage before bonding by said bonding means.
 14. A scanning probemicroscope provided with a probe tip part provided so that a probe tipfaces a sample and a measurement part for measuring a physical quantityoccurring between said probe tip and said sample when said probe tipscans the surface of said sample, wherein this measurement part holdssaid physical quantity constant while said probe tip scans the surfaceof said sample so as to measure the surface of said sample, said probetip is comprised of a nanotube, a base holding this nanotube, and abonding means for bonding said nanotube to said base, and said bondingmeans is a coating film provided over the entire circumferences of saidnanotube and said base.
 15. A scanning probe microscope as set forth inclaim 13, characterized in that said probe tip part is a cantileverhaving said probe tip at its front end.
 16. A probe used for a scanningprobe microscope or electron microscope, said probe characterized bybeing provided with a probe tip comprised of a nanotube, a base holdingthis nanotube, and a bonding means bonding said nanotube to said baseand is stripped of a contamination film formed by an observing means ata stage before bonding by said bonding means.
 17. A probe used for ascanning probe microscope or electron microscope, said probecharacterized by being provided with a probe tip comprised of ananotube, a base holding this nanotube, and a bonding means bonding saidnanotube to said base, said bonding means being a coating film providedover the entire circumferences of said nanotube and said base.